Detonating fuse



.3am E7, 195@ R. L. GRAUMANN DETONATING FUSE Filed May 4, 1938 PatentedJan. 17, 1950 (@Granted underv the: act of March 3, 1883, as amendedApril. 30, 1928; 370 O. G. 757-)y 9 Claims.

This invention relates. toa fuse for detonating the bursting charge of aprojector and has among its several objects:

To` provide a fuse thatA will cause the burst of a projectile with highorderl detonation after a delay that permits penetration of an armorplate;

To provide means to maintain the fuse in unarmed condition until after`ring;

Tol provide centrifugally operated means for conditioning the fuse fordetonation;

To provide a fuse with the parts so arranged that While inl the unarmedcondition the detonal tor ofthe fuse maybe exploded Without affectingthe booster charge carried by the fuse or the bursting charge of theprojectile in which the use is assembled;

Toprovide novel meansfor locking the movable parts of the fuse in ringposition.

In the drawings:

Fig. i is a longitudinal section of my novel fuse in. the unarmedcondition;

Fig- 2 isa detailed sectional view, substantially at right anglesto theplane of Fig. 1, of a portion of the iuse.- illustrating the relation ofthe parts in the iiring position;

Fig. 31s av fragmentary view on a. larger scale disclosing the. novelmeans for' locking thev parts in the ring position;

Fig, 4 isan enlarged detailed view, in section, ofv the. delay element;

. Fig, 5 is a fragmentary sectional view disclosing the relation of:certain parts of the fuse in the unarmed position;

Fig. 6 is a transverse section taken on the line 6 6., Fig. 1 showingthe guide and anti-friction means: for theauxiliary plunger..

The fuse constituting the subject of the present invention is intended.for use in the base of a projectile, and in com-.mon with other fusesvof this general type the body 'I- is provided with screw threads 8Y forengaging threads in the fuse opening in the projectile. If desired,tracer charge a may be inserted or the space designed to receive thetracer may becl'osed by a plug if the tracer is not used.A

The movable parts of the fuse comprise an auxiliary plunger l0 providedwith longitudinal grooves II wherein are mounted ball bearings I2 to;-guide the auxiliary plungerl in the body 'l and permit free movementthereof byl momentum upon impact of the projectile, the balls being heldin position by a hall retainer i3.,

- hnmediately` ahead o the,v auxiliary plunger and contactv therewithis' the plunger I4 that Plonger I4'. is formed unarmed position, asshown in 1. The rotation of the projectile after firing sets upf cen.-trifugal forces that moverthe; detenta t6 outwardly and permit the.plunger I5 tomove! forwardly upon impact of the. projectile;y but suchforward movement before impact. is prevented' by anti-creep spring I'I:that tends to hold the plunger i5 in they unarmed position. Otherdetents t8 are provided in the fuse: capy la between the firing pin 25Yand the forward end of, the delay element, thus providing anadditionalsafety factor until after the projectile is red.

The delay element 50,v shownin detail in. Fig. 4, is mounted in theplunger I5 Where it retained by engagement of screw threads 21. withcoacting threads in the plungerv I5. At the forward end of the delayelement is ay sensitive primer Z2 seated on primer retaining cup 5-Ifin. primer con,- tainer 52 and disposed to be struck: by firing pin 2Bwhen the parts are moved; into firing position, as seen in Fig. 2 uponimpact of the projectile The expansion of the products resulting. fromthe explosion of primer22 effects. two results:

First, the ring pin 23 that is normally held inoperative by a shear pin2-4 is driven to explode the primer 25 which has an anvil 26 tocooperate with the firing pin;

Second, the cup 2,1 of deformable metal,v for example copper, isexpanded into recesses 28- in the'cap iii andthereby locks the parts ofthe fuse in the ring position with all the; elements correctly alignedto transmit the explosion as desired, the gases passing through openings53, to act upon cup 2l. The deformation of the cup 2l into the recess 28is shown on an enlarged scale. in Fig. 3.

The flames and hot gases resulting from the explosion of primer 25 arecaused to pass through a baiiie- ZS having a. chamber 30 communicatingwith primer 25 by passages 3i in anvil 2:5 and thence by radial openingsSZl to longitudinal grooves 33 and thence to the delay pellet 34.

The passage ofv the hot gases. into the forward part of the fuse body isprevented by an obturating ring 35 of lead or other suitably plasticmetal that is squeezed out into tight contact with the plunger I5 byplacing the pellet container 54 in position in the plunger, placing thelobturating. ring 35 thereon, seating the baffle- 29 against theobturating ring. 35 andapplying. pressure te the baffle to deform. theobturating ring the 'plunger i5..

Mounted in the plunger I5 adjacent delay pellet 34 and in communicationtherewith through opening 38 is the detonator charge 31 with detonatorlead-outs 38 to propagate the ignition to booster charges 39 that areretained in position by a cup 40 surrounding fuse body 1. Pins 4I fixedin plunger I5 slide in grooves in the fuse body 1 to maintain thelead-outs 38 in position to register with the booster charges 39 whenthe parts are moved to the ring position.

When the fuse parts are in the unarmed position the lead-outs 38 are outof alignment with the booster charges 39, as seen in Fig. 5', andconsequently accidental explosion of the detonator 31 would not ignitethe booster charges 39 due to the fact that the lead-outs are sealed olffrom the booster charges by the close fit of plunger I5 with fusebody 1. However, when the projectile is fired the rotation thereofcauses the detents I6 and I8 to be moved outwardly, leaving the plungersII) and I5 free to move forwardly but such movement is prevented byspring I1 until impact of the projectile. Upon such impact the inertiaof plunger I5 supplemented by that of the heavier auxiliary plunger I0causes the plungers to move forward and strike primer 22 against ringpin 2D, the explosion of primer 22 exerts sufficient force upon iiringpin 23 to shear pin 24 and drive the firing pin 23 against primer 25which in turn ignites delay pellet 34 and from the delay pellet theignition is propagated to detonator 31 and thence by detonator lead-outs38 to booster charges 39 which re the bursting charge of the projectile.

Pins 42 extend through fuse cap I9 to secure the iiring pin 20 inposition and caps 43 close the outer ends of the spaces 28 into whichcup 21 is expanded to lock the parts in iiring position. Cap I9 issecured to fuse body 1 by drilling through the cap and into thefuse bodyafter assembly, tapping the hole thus made in the fuse cap and securinga set screw 44 therein.

The invention herein described and claimed may be used and/ormanufactured by or for the Government of the United States of Americafor governmental purposes without the payment of any royalties thereonor therefor.

I' claim:

1. A projectile fuse, comprising a body'having a cavity therein, boostercharges in said body, a plunger and an auxiliary plunger Yslidable insaid cavity, anti-friction means between said auxiliary plunger and saidbody, centrifugally releasable means to retain said plunger in aninitial position; a detonator, detonator lead-outs adapted to be broughtinto registry with said booster charges by impact after the projectileis red and a delay element in said plunger; said delay element includinga first ring pin, shearable means to hold said firing pin in inactiveposition, a primer disposed to be strikable by said firing pin, a delaypellet adjacent said detonator, a baille element between said primer andsaid pellet, and obturating ring between said delay element and saidplunger, and a sensitive primer disposed to shear said shearablemeansand drive said ring pin against the rst mentioned primer when saidsensitive primer is detonated, there being passages leading outwardlyfrom said sensitive primer; a deformable cup enclosing a portion of saidplunger and overlying said passages; a cap on said body, a second ringpin in said cap to strike said sensitive primer, centrifugallydisplaceable means between said second firing pin and said delayelement, there being recesses in said cap into which said deformable cupis expanded by the detonation of said sensitive primer to lock saidplunger in the forward position to which it is moved by impact wherebyalso said sensitive primer is caused to strike said second ring pin.

2. A projectile fuse, comprising a body having a cavity therein, boostercharges in said body, a plunger and an auxiliary plunger slidable insaid cavity, centrifugally releasable means to retain said plunger in aninitia1 position; a detonator, detonator lead-outs adapted to be broughtinto registry with said booster charges by impact after the projectileis fired and a delay element in said plunger said delay elementincluding a iirst firing pin, shearable means to hold said iiring pin ininactive position, a primer disposed to be strikable by said ring pin, adelay pellet adjacent said detonator, a baiile element between saidprimer and said pellet, and a sensitive primer `disposed to shear saidshearable means and drive said iiring pin against the iirst mentionedprimer when said sensitive primer is detonated, there being passagesleading outwardly from said sensitive primer; a deformable cup enclosinga portion of said plunger and overlying said passages; a cap on saidbody, a second firing pin in said cap to strike said sensitive primer,centrifugally displaceable means between said second ring pin Y and saiddelay element, there being recesses in said cap into which saiddeformable cup is expanded by the detonation of said sensitive primer tolock said plunger in the forward position to which it is moved by impactwhereby also said sensitive primer is caused to strike said secondfiring pin.

3. A projectile fuse, comprising a body having a cavity therein, boostercharges in said body, a plunger and an auxiliary plunger slidable insaid cavity, anti-friction means between said auxiliary plunger and saidbody, centrifugally releasable means to retain said plunger in aninitial position; a detonator, detonator lead-outs adapted to be broughtinto registry with said booster charges by impact after the projectileis iired and a dlay element in said plunger disposed to ignite saiddetonator; a primer carried in the forward end of said plunger, therebeing lateral openings through said plunger adjacent said primer, adeformable cup disposed around said end of the plunger and overlyingsaid openings; a cap on said body, and a firing pin in said cap disposedto strike said primer when said plungeris moved forward by impact afterthe projectile is fired, there being recesses in'said cap into whichsaid cup is expanded by the detonation of said primer to lock saidplunger with said lead-outs in registry with said boosters.

4. A projectile fuse, comprising a body having a cavity therein, boostercharges in said body, a plunger and an4 auxiliary plunger slidable insaid cavity,'centrifugally releasable means to retain said plunger inaninitial position; a detonator, detonator lead-outs adapted to be broughtinto registry with said booster charges by impact after the projectileis iired and a delay element in said plunger; said delay elementincluding a first iiring pin, shearable means to hold said firing pin ininactive position, a primer disposed to be strikeable by said ring pin,a delay pellet adjacent said detonator," a -baffle element between saidprimerY and said pellet, an obturatingring between said delay elementand said plunger, and a sensitive primer 'disposed to shear saidshearable means and drive said iiring pin against the first mentionedprimer when said sensitive'primer is detonated, there being passagesleading outwardly from said sensitive primer; a deformable cup enclosinga portion of said plunger and overlying said passages; a cap on saidbody, a second iiring pin in said cap to strike said sensitive primer,centrifugally displaceable means between said second firing pin and saiddelay element, there being recesses in said cap into which saiddeformable cup is expended by the detonation of said sensitive primer tolock said plunger in the forward position to which it is moved by impactwhereby also said sensitive primer is caused to strike said second ringpin.

5. A projectile fuse, comprising a body, a plunger slidable therein,means releasable by rotation after firing to retain said plunger in aninitial position, a delay element in said plunger, means to propagateignition from said delay element to the explosive charge of aprojectile, a primer carried by said plunger to initiate functioning ofsaid delay element, means to detonate said primer upon movement of saidplunger to a predetermined position by impact after ring, an expansiblemember disposed around said primer to be expanded by explosion of saidprimer, and a member adjacent said expansible member, when said plungeris in said predetermined position, having cut away portions to permitexpansion of said expansible member and engage said expansible member tohold said plunger in position to propagate ignition to said explosivecharge of a projectile.

6. A projectile fuse, comprising a delay element including a container,a delay pellet therein, a baie having one end seated against said pelletand a laterally extending flange at its other end and devious passagesthrough said baiile, an obturating ring of plastic metal between saidflange and an end of said container; a primer seated` upon the flangedend of said baille, a firing pin disposed to be movable against saidprimer, shearable means holding said ring pin normally away from saidprimer, a second primer disposed to drive said ring pin against, thefirst mentioned primer when the second primer is detonated, and meansdisposed to be deformed by the products of detonation of said secondprimer and adapted to lock the aforesaid parts in the positions occupiedby them at the time of detonation of said second primer.

7. A projectile fuse, comprising a delay element including a container,a delay pellet therein, a baie having one end seated against said pelletand a laterally extending ange at its other end and devious passagesthrough said baille, a primer seated upon the flanged end of saidbaiile, a firing pin disposed to be movable against said primer,shearable means holding said firing pin normally away from said primer,a second primer disposed to drive said ring pin against the firstmentioned primer when the second primer is detonated, and means disposedto be deformed by the products of detonation of said second primer andadapted to lock the aforesaid parts in the positions occupied by them atthe time of detonation of said second primer.

8. A projectile fuse, comprising a body means movable in said bodyincluding a delay device to propagate ignition to the explosive chargeof a projectile, elements releasable during flight after firing toretain said means in an unarmed position until after firing', said meansbeing movable to armed position by impact after release of saidelements, a primer disposed to initiate, by

its detonation, the functioning of said means, means to detonate saidprimer when said means is moved by impact as aforesaid, said movablemeans including means expansible by the products of detonation of saidprimer to lock said movable means in the armed position occupied therebyat the time of said detonation of said primer.

9. A projectile fuse, comprising explosion initiating means including aprimer and a delay device, said means being movable from unarmedposition to ring position by impact ofthe proj ectile, means to detonatesaid primer when so moved, and expansible means disposed around saidprimer to be expanded by the products of detonation of said primer tolock the aforesaid explosion initiating means in ring position forinitiating the explosion through its said delay device.

RAYMOND L. GRAUMANN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,197,414 Watson Sept. 5, 19161,311,104 Watson July 22, 1919 1,438,328 Pistorio Dec. 12, 19221,462,313 Woodbe July 17, 1933

